Many simple communication networks lack control information. Control information comprises routing information, network health information, node outage information, status of remote network nodes, etc. As networks have become more complex, carry more data, and are relied upon more for communication, the ability to transfer control information between nodes becomes more important.
Some networks or network portions use a communication path or line that is entirely separate from the data link to transmit control information between network nodes. Using separate control paths adds complexity and expense to networks.
In other networks or network portions, however, control information is transmitted between nodes over data links, eliminating the need for distinct control paths. Some of these networks assign a portion of the data bandwidth to carrying the control signals, which therefore modifies the transmitted data. Other networks set aside a distinct bandwidth to transmit the control signals over the data link. Because that bandwidth cannot be used to transmit other data, this method reduces overall data handling capacity for the network.
It would thus be desirable to provide a method for transmitting control information over a data link without reducing or affecting data handling capacity.